https://www.epo.org/en/service-support/faq/myepo-services/central-fee-payment/claiming-refunds/how-can-i-claim-refund

How can I claim a refund online?

If you’ve received two letters from us (an advice of refund and a refund code): Sign in to Central Fee Payment using either two-factor authentication or email address plus password. Select Claim refund, select the relevant procedure (EP, PCT or UP) and enter your patent application number and the refund code you received by post. You can then select Refund to bank account or Refund to deposit account held with the EPO. 
If you’re a registered user of MyEPO and Mailbox and are entitled to claim a refund directly, i.e. without a refund code (e.g. either as an applicant or as a representative): Sign in to Central Fee Payment using two-factor authentication, go to Refunds and then Claim refund without refund code. There you will see an overview of all the refunds you can claim. You can either select all refunds visible on one page (up to 25) or select each one individually and have them paid directly to a bank account or EPO deposit account.

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